Rain induced co-channel interference at 60 GHz and 300 GHz frequencies

Results at mm wave frequencies have shown that it is important to evaluate co-channel interference between directional beams that cross each other. Terahertz frequency bands, especially around 300 GHz, has been considered for future wireless communications. As far as we know, no work has considered the rain induced interference at THz frequencies. In this work, we evaluate the rain induced interference at 300 GHz. Results are calculated also at 60 GHz in order to make a comparison. We combined bistatic radar equation, first order multiple scattering approximation and full Mie scattering calculations to existing drop size distribution models to estimate interference due to rain. Considered effective path lengths between transmitter and receiver are 100 m and 500 m and the effect of selected drop size distribution is studied. Overall interference levels was observed to be approximately 20 dBm smaller at 300 GHz than at 60 GHz and angular dependency of interfering power was much more forward oriented for 300 GHz frequency. The results show that rain induces interference has significantly different behaviour at THz as compared to lower frequencies.